Star Vs the Forces of Gravity Falls: Oneshots
by MagicMoneyPants
Summary: After an… incident, 14-year-olds Dipper and Mabel have to change schools for the rest of the semester. There they meet a magical princess from another dimension and her best friend. It's business as usual for the Mystery Twins, but can the Mess-up Twins cope with the two people on Earth who aren't fazed when things get weird and wild?
1. The Mystery Twins Meet the Mess-Up Twins

**.**

 **The Mystery Twins Meet the Mess-Up Twins**

 **.**

"Marco Diaz and Star Butterfly to the principal's office." The voice over the intercom announced. "Marco Diaz and Star Butterfly to the principal's office."

As the pair of friends left their class, Marco whispered, "What did you do?!"

"Nothing!" The princess answered, before pausing to think. "Recently."

The boy released a long-suffering sigh, while the blonde skipped beside him. Quickly reaching their destination, Marco knocked on the principal's door. The man from beyond told them to enter.

"Ah. Marco and Star." Principal Skeeves began. "I'd like you to meet our two newest students."

He gestured to the other teens in the room.

"These are Dipper and Mabel Pines. They've just transferred to our district."

When he finished, the two kids waved. Star and Marco looked at the new arrivals, immediately noticing their similarities. They were obviously siblings, and probably twins.

"I want you two to show them around." Skeeves continued. "Since you're an experienced school guide," He looked at Marco, "And you're our newest exchange student." He nodded to Star.

"Uh, sure." Marco answered.

"Great!" The principal pushed them out of his office without another word.

::::::::::::::::::

The new girl jumped forward, sticking out her hand. "Hi, I'm Mabel! I'm 14 and own a pig! Wanna be BFFs?"

"Okay!" Star vigorously shook her hand, followed more hesitantly by Marco.

"This is my twin bro Dipper." She said. "He's kinda a dork, but not too bad once ya get to know him."

Dipper rolled his eyes. "Thanks Mabel. Thanks for that." And shook their hands as well.

"I like your hearts." Disregarding any concept of personal space, the brunette girl stepped forward and booped Star's cheek. "What kinda makeup do you use?"

"Oh, they're natural." Star explained. "You see: _I'm a magical princess, from another dimension_!"

Marco was impressed when only the rainbow caught fire after Star summoned it, leaving the school unharmed. But now came the difficult task of explaining his friend's presence.

"Hmm, neat." The twins responded to the display of magic.

Well, that was… unexpected.

"What dimension are you from?" Dipper asked, finally engaged in the conversation.

Definitely not the usual response.

"I'm from Mewni."

The boy closed his eyes, searching his memory. Finally he said, "I'm not familiar with that one, but welcome to Dimension 46'\\."

Star gave him a blank look, mirrored by Marco.

Dipper chuckled anxiously, rubbing the back of his neck. "Sorry. I guess the trouble with infinite universes is that Standardized Designations don't really mean anything."

"Oookay…" Marco ushered the new students towards a classroom. "Let's start here. We're all in Miss Skullnick's homeroom."

::::::::::::::::

After the bell rang, the quartet exited the class with everyone else.

"So." Dipper began. "I noticed our homeroom teacher's a troll."

"Yeah." Star chewed on her wand nervously. "That was kinda my bad."

 _Finally!_ Marco thought. _Here it comes._ Whenever people experienced Star's magic for the first time, they went through three stages: Terror, denial, and a sort of confused-acceptance.

"And no one has a problem with it?"

 _Wait, what?_

Star scrapped her foot across the ground bashfully. "Honesty? She kinda looks better this way."

"Makes sense." Mabel commented.

While Marco couldn't disagree with Miss. Skullnick's appearance, the fact that these guys weren't fazed by their teacher being a _completely different species_ was unacceptable.

"Okay. Who are you?" The boy demanded.

"We are…" Mabel mimicked Star's movements from earlier (aside from the flaming rainbow and random critters). "The _Mystery Twins!"_

"C'mon Mabel." Dipper slapped his forehead. "It's okay when we call ourselves that, but the name's still embarrassing."

"Only if you let it be." His sister stuck out her tongue.

"Anyway." The boy turned back to his guides. "Let's just say we're used to this kinda thing."

Marco was about to scoff at the claim, but Star interrupted.

"You mean you know about Earth Magic?!"

"I guess so?" The brunette answered. "I never thought to consider it unique to Earth before."

The Princess turned to her friend. "And you keep saying magic doesn't exist here."

"It doesn't!" Marco shouted. "He's making stuff up!"

Mabel looked at the boy sympathetically. "Hey, it's okay. It's not like it's a well-known fact."

"Yeah." Dipper agreed. "It typically only congregates around natural soft spots in reality."

"This makes absolutely no sense." Marco said.

"Trust me, we've been studying this stuff for the past two years."

Mabel rolled her eyes. " _He's_ been studying it. I'm just there to save his butt!"

"Hey! You only rescue me 50% of the time _at most."_

The twins stuck their tongues out at each other.

" _Bleh!"_

 _"Bleh!"_

"I like these guys!" Star bounced on her heels.

:::::::::::::::

After school, Dipper was ready to part ways with their tour guides, but Star insisted that the twins walk home with her and Marco. Mabel, of course, agreed. It was obvious the girls had found a kindred spirit in each other, but the Pines boy was surprised by how much attention was paid to him. At every opportunity, the princess would quiz him on 'Earth Magic'. While usually eager to share his thoughts and theories, Dipper revealed as little as possible. After all, y'know, _trust no one._

Then there was Marco. After years of being bullied, Dipper recognized animosity when he saw it. Based off their guide's personality and interests, the teen saw him as a potential friend. Apparently the feeling wasn't mutual. From what he understood, Marco had spent a ridiculous amount of time convincing his bestie that magic didn't exist on Earth. Now all that work had been undone. The boy didn't trust the newcomers, the irony of which wasn't lost on Dipper.

"So why exactly did you transfer here?" Marco asked.

"Our school burned down." Dipper answered.

"In a totally unsuspicious way." Mabel added quickly. "The police report said it was an electrical failure, not arson at all. So, y'know, we weren't involved. We have a solid alibi too."

"Oookay…"

Dipper slapped his forehead again.

:::::::::::::::::::

When the Diaz residence came into view, something _strange?_ happened. A tear in space appeared in front of the teens, and a battalion of monsters jumped out.

"Ludo!" Star growled, eyes narrowing.

"Get behind us!" Marco shouted at the twins.

But Dipper and Mabel had already run forward, knocking down a nameless minion in the process. The girl pulled something from beneath her sweater and cried, "Grappling-hook!" firing it at another creature's head.

Meanwhile, Dipper drew two black objects from his backpack. He tossed one to his sister, then slipped the other over his fist, K.O.-ing Deerbeard with the knuckleduster.

Well-armed, the twins made short work of the monsters. Mabel kicked Spikeballs in his spike-balls, as Dipper manhandled Man Arm.

Marco and Star were as confused as Ludo. Dipper used this opportunity to charge the diminutive leader. He knocked away Ludo's staff, and held the tiny monster in a chokehold. "Stand down!" He barked at the army, while their leader turned blue.

Mabel took her place beside her brother, an intimidating glare on her face.

Shaken out of her stupor, Star yelled, "No! Stop!"

Surprised by the demand, Dipper dropped Ludo, who scooted a few feet away.

The princess marched up to the siblings and said, "That's not how we do things!"

"But," Mabel stammered. "But they attacked us."

"They always attack us!" Star fumed. "That's their thing!"

"You mean this has happened before?" Dipper asked incredulously.

Remembering these guys were new, the blonde calmed down (but only slightly), "Ludo has been trying to steal my wand since I got it. He comes after us, like, every other day."

The twins shared a glance. "And you haven't, y'know, gotten rid of him?"

Star and Marco gaped in shock.

"No, no, no!" Dipper waved his hands and hurried to explain. "I didn't mean kill him ( _not necessarily_ ). I meant, like, imprison him, or banish him to the outer void, or something."

"He's not really that much of a threat." The girl said. "We can handle him. Plus it's kinda fun to beat them all up."

Dipper looked away and rubbed the back of his neck.

Hoping to mend the conflict, Mabel said, "Maybe it's a cultural thing? We're kinda used to enemies trying to kill us, so, y'know, we just jumped into things."

Star let out a sigh. "It's okay. You're warriors, and you acted as such." Then she lifted her head, and took the tone of the leader she was destined to become. "But this is my fight, and you will follow my orders."

Marco had never seen this side of his friend, he was as shocked as the newcomers by her commanding presence. The twins nodded in consent.

But before Ludo could skulk away, Dipper stopped him. Having experienced a transdimensional invasion firsthand, and determined to not let it happen again, he said, "Earth and all its inhabitants are under the protection of the Pines. If you don't know that name, ask the Nightmare Realm."

"And I'm keeping your hat!" Mabel added, plucking the carnivorous-cow skull off the monster's head, and placing it on her own.

Ludo and his army made a hasty retreat. The friendly atmosphere slowly returned, and everyone calmed down.

Except for Marco, who screamed, "What the hack is going on here!?"

::::::::::::::::::::

 **.**

 **.**

I like both these shows, and the idea of the characters meeting (especially since they all live in California during the school year). I also like the idea of the twins being so used to magic at this point that they're completely unfazed by anything weird happening around them (They may seem a little OOC towards the end, but think about it: Underneath all the humor, Dipper and Mabel experienced some _really_ horrific things in Gravity Falls. Now add a second eventful summer to that. I think by age 14 they'd be pretty hardcore {and emotionally traumatized} but mostly hardcore).


	2. What To Do If You Raise The Dead

**.**

 **What To Do If You Raise The Dead**

 **.**

There was a tradition among Echo Creek's high school student's: Every autumn, those brave enough would travel to _Isolation Point,_ and spend the night at the pioneer cemetery there. Over the years it became less of a right-of-passage, and more of a party with age-appropriate beverages and an improvised sound system.

This was the first year Marco and Star could attend, and Mabel (and by extension Dipper) wouldn't give up the opportunity to join in. The four teens entered the clearing where a bonfire lit the center. Only a few what-might-have-been gravestones suggested this was the right place, but the music and kids with red plastic cups made it clear that accuracy didn't matter.

The group dispersed according to their nature. Star and Mabel gravitated to the center of attention, while the boys drifted to the outer rim.

Dipper was almost within the tree-line when a voice stopped him. "Hey. It's cool you were able to make it."

"Uh, yeah." The boy turned. "Just tryin' to, y'know, get in the spirit of things."

"Nice, nice." Jackie Lynn Thomas stepped closer, offering him a miscellaneously safe drink.

Dipper took it gratefully.

"So, I gotta ask: Are the rumors about you true?"

To his credit, Dipper only choked a little bit. "What? No, no, no! We were home the whole time! The police report said the fire was caused by a faulty electrical system."

"Uh… I meant the other rumor."

The brunette pinched the bridge of his nose. "Not the Pinecest thing? I thought we left that behind us at our old school."

Jackie quirked an eyebrow. "What's Pinecest? Some kinda air-freshener or something?"

"Uh, yeah…" Dipper's eyes shifted nervously. "It's an air-freshener… So, what rumor were you talkin' about?"

"Er, well, like that you talked back to Brittney Wong."

"Oh, that." The boy relaxed. "I've dealt with girls like her before, it's no big deal."

Jackie looked at him skeptically.

"Plus it's not like I'm gonna be here too long." He added bashfully. "So it doesn't matter who I upset."

"Well, either way, that's still pretty rad."

"Nah." Dipper propped himself against a tree, his fake confidence reasserting itself. "Like I said, nothing out of the ordinary for me."

Jackie leaned next to him. "Hey, maybe you and me could, y'know, hang out sometime."

Dipper spat out his drink. "Wait, are you- that is- um- is that- did- are you asking me out on a date?"

The girl's cheeks flushed slightly. "Yeah, I guess I am."

"Wow. Wow." He shook his head, trying to clear his thoughts. "I was not expecting that."

Jackie giggled. "So, what do you say?"

"Oh man. I wish I could say yes."

The girl's face fell.

"No, no! In any other situation I would!" Dipper waved his hands defensively. "I mean, you're like, the coolest girl in school. I'd have to be crazy not to want to go out with you."

That just made her look confused.

"The thing is, a friend of mine has a crush on you, and it would be really crumby of me to go out with you knowing that."

While not back to her usual self, Jackie did brighten up. "Oh yeah? Who's your friend?"

"I can't tell you." Dipper rubbed the back of his neck. "That's for him to do."

The girl stood silently for a while.

"But it would be cool if we could hang out together." The twin said. "Y'know, as friends."

Jackie smiled. "Yeah, as friends."

" _Corpus Levitus!"_

"Wait. Did you hear that?" Dipper said.

"Hear what?"

" _Diablo Dominus!"_

"Crud!" The boy ran off. "No, don't!"

" _MONDO VICIUM!"_

Too late! Dipper came upon Janna and some of her friends standing around one of the pioneer graves.

The ground shook. A fissure opened in front of the kids. A rotting corpse dragged itself out of the hole. The girls screamed, except for Janna who looked on in wide-eyed excitement, until the ghoul grabbed her leg.

A rock crashed down on the zombie's head, and Dipper shouted, "Run!"

More cracks opened as the girls joined the main group. New screams erupted as the zombie horde approached the high schoolers. Dipper grabbed the shovel used to dig the fire pit (at least, that's what he hoped it was there for. After the blatant misuse of dark magic, he couldn't be sure), and started decapitating the undead. A grappling hook whizzed past his head, followed by a narwhal blast. After a well-placed kick reduced a ghoul to dust, Marco stood next to Dipper, followed by Star and Mabel.

"Dipper, what did you do?!" - "Star, what did you do?!" Mabel and Marco shouted simultaneously.

"It wasn't me!" The other pair answered in sync.

"It was Janna." Dipper explained.

"Hey! I didn't know it would actually work!"

"What do we do now?" Mabel asked. "Explode their heads again?"

"No time. We're surrounded." Dipper said. "We need to get to a defensible position first."

Taking charge, the boy continued.

"Star! You're on point. Use your wand to blast us a path out of here. Mabel, Marco, you two flank us. Make sure the group stays together, and get the zombies that try to surround us. I'll take up the rear."

"Ha! _Rear_."

"Mabel! This is serious!"

::::::::::::::::::

Assuming their positions, the four teens herded their peers through the forest. It wasn't hard to outrun the zombies' shuffling gait, but the fight wasn't over. They paused at a chasm with a rope bridge. While their classmates crossed in single file, the four friends stood aside to talk.

Still in command, Dipper spoke first. "Okay. You two," He pointed to his sister and Marco. "Get everyone to high ground. Me and Star will hold the zombies here."

Star nodded, wearing her 'serious' face, but Marco was having second thoughts. "By yourselves? But we can take the zombies out together."

The other boy shook his head. "We don't know how many there are. We have to get the others to safety in case we die."

"Wait. What?"

"Lead them out of here, then come back to help us. We have to contain this here."

"He's right Marco." Star laid her hand on the boy's shoulder. "With my wand and the bridge, I could hold this place on my own. Keep the others safe, and we'll wait for you to get back."

Of course Marco saw the logic in the plan, but that didn't mean he had to like it. Strangely enough, Mabel seemed fine with leaving her brother to face death's jaws. Reluctantly, the boy crossed the bridge, and led his classmates along the path.

::::::::::::::::::

It wasn't long before the undead entered the clearing.

"We've got them bottlenecked, we just gotta hold them here."

Star rolled her eyes. "I know military tactics, I had the royal guard as my babysitters."

A goofy grin overtook the princess' face. _So, you jab your thumb in there until you hear a sound like a grape popping. And once you don't feel any more pressure, you done it._

A shovel bashed the ghoul that was about to bite Star's neck.

"Oh. Right." She started blasting zombies.

:::::::::::::::::

By the time Mabel and Marco got their classmates to safety and returned to the battle, their friends were on the near side of the bridge, preventing zombies from crossing.

"You're pretty good with that thing." Star panted.

Grunting, Dipper managed to say, "Yeah, the shovel's a really underrated weapon. It can chop, thrust, and bludgeon. As an added bonus, you can also use it as a shovel. You're not so bad yourself."

"Well, y'know, it's a talent." She aimed her wand. "CHINCHILLA BOMBARDMENT!"

While fluffy rodents murdered a row of zombies, the others ran forward.

"So. What's the plan?" Mabel asked.

"Finally!" Dipper said. "Star, cut the bridge."

The blonde followed his orders (something she'd wonder at later, considering she was a princess and all).

Dipper flipped through his phone, before looking at the other boy, "Marco! Do you know the words to _Disco Girl_?"

Rubbing the back of his neck, he said, "Maybe."

"Then sing man!" Dipper started the music on his phone. "Sing for your life!"

The twins sang along to the tune, and after some prompting, got Marco to join. All the while, Star recorded the event on her friend's phone, giggling, "Hehe, so cute!"

But, despite the adorableness, the zombies wailed in pain as their heads exploded one by one. It wasn't long before the undead horde was destroyed.

"What… What the heck just happened?" Marco asked.

"Zombies can be killed with a perfect three-part harmony." Dipper explained nonchalantly.

"And you totally nailed it dude!" Mabel socked the boy's shoulder. "Have you ever thought about taking up singing?"

"Oh, um…"

"Well you should." Mabel wrapped a more-than-friendly arm around him.

"That was awesome!" Star exclaimed. "I can do that too!" The princess lifted her wand and let a warbling sound emanate from it.

The twin slapped his forehead. "Guess I should've mentioned that earlier."

"Ya think?" Marco tried to pull himself from Mabel's grasp.

Dipper sighed. "Well, we should probably get everyone back home. We should also figure out where Janna learned that spell from. Where are they?"

"Oh, we sent them up a condemned lookout tower." Mabel said. "Probably gonna need the fire department to get them down actually."

Dipper pinched the bridge of his nose. "High ground?"

"High ground." Mabel chirped.

:::::::::::::::::::


End file.
